Prism-lens unit



July 1-7, 1928. 1 ,67'7, 5 9b C. F. JENKINS PRISM LENS UNIT Filed July1, 1925 20 and particularlj pointed dut in the claim.

Patented July 17,1928;

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Applicaitlen filed 311171,

This. invention relates to apparatus for .use in radio vision and in thetransmission of motion pictures byradio, and has for its principalobject a more flexibly ad1ustable mechanism than heretofore employed.Infm'echanism's previously used for the vertical and transverse scanningof a flatc picture plane, real or imaginary (aerial), the devices whichgave movement in both directions operated on the same plane, that is,both the orlzontal and vertical traverses sweep across va single imageplane of the lens, the opposite focus of which is on the picture-object.This involved certainannoying limitations w ich are avoided by the.

method of. getting movement in one direction in one focal plane and thetransverse movement in another focal plane, as hereina r disclosed,illustrated in the drawings,

In the drawings Fig. 1 is a diagrammatic illustration .of the scheme asemployed i'nfa receiving machine, and Fig. 2 the same employed m asending machine. both figures like symbols refer to hke parts, in whichA is a light source; a lens for imaging the light source onto a screenG, through a rismatic ring D (Patent No. 1,385,325). is a ens disc havmiequ1- s spaced, circularly arranged lenses t ereon,

' each of which comesinto action in succession to swee the light sourcetransversely in the plane which may be a white screen. In Fig. 2 thelighted figure A is the light source, and for the white screen in thefocal plantfF a. light-sensitive cell is substituted, the method ofoperation. being the sarne in both cases, i. e., both sending andreceiving.

Referring to Fig. 1, a rece1ving device, as 40 perhaps the easier toillustrate the method,

let it. be assumed that the light source .sharply imaged or focused onthe screen C as a spot. But as the light passes through the top of theprismatic ring D the ray 1s,-

deflected from its axial line and the spot appears rat the topaof thescreen (3. But when thefprismatic ring is rotated the constantlychanging angle of the prism causes the light spot to travel downward ina straight line. on the screen until it reaches its lowestpoint'of'travel. v

A is lpart of this. invention, it

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That is, the rotation of the prismatic ringsweeps the image of the lightsource in a vertical line, say, from top to bottom ofthe screen C. Ifthe spot so travels every onesixteenth of a second, then persistence ofvision deceives the eye into the belief that it is a complete,lightedline, whereas the eye only-sees an approximately round {spot oflight in an infinlte succession of 'imagi nary positions in a-straightline from top to bottom of screen C; and the middle lens on lens disc Eat rest-would image this. line as a vertical line on the screen F.

If, however, the lens disc E 'isin, rotation, then the lenses on lensdisc E will cause the image-spot of light to sweep transversely acrossthe screen F as many times as there are lenses passing during thetime ofone rotation of-prism D, two hundred, for example, and the whole surfaceofthe screen.

F will seem to be lighted, for 'thevertically moving spot on screen 0 issimultaneously given two hundred transverse movements in the plane F,the common focal plane of all the disc-mounted lenses. v e I To furtherillustrate, it may be ointed out that when the spot is at the top 0screen 0 it is swe t'transversely across the bottom of screen when it isat the bottom of its travel on screen C, then it is swept across the topof screen F; and one hundred and ninety-eight other times acrossscreen Fat successive levels between the first and last line, "And, as notedabove, if'this all hap ns every sixteenth of a. second the screen seemsto be lighted over its ,whole surface.

As the means for varying the strength of ,the light by radio in adefinite order to buildup a picture on the screen F is no is not hereillustrated.- c

It can well .be understood that where line speeds, of the low orderassumed above, occur at the rate of 192,000 per minute, usual radiopicture mechanism methods are not adequate, and, therefore, any methodwhich" increases the permissible latitude in operation or mechanism ishighly desirable. 100

What I claim, is- Y In apparatus mf the class described, a

.fixed source of light, a screen, .a-lens for lenses, each- 0f which insuccession moves concentrating a-point of light from the light acrosgthe optical axis of said first lens and source in a focal plane, meansfor scanning means for rotatingsaid prismatic ring and 10 V the screenwith the said point of light as a lens carrier in synchronism l 5 spoton the screen comprisinga prisgnatic In testimony whereof I 'haveafiixedmy ring located in the optical axls of the lens, signature. I ,r a.rotatable carrier having; a. plurality of CHARLES FRANCISJENKIN S. a

